Questions: How many molecules are in 89.0 g of tetraphosphorus decoxide? 2.59 × 103 1.89 × 10^23 7.19 × 10^31

Solution Steps

• The chemical formula for tetraphosphorus decoxide is \( \text{P}_4\text{O}_{10} \).
• Calculate the molar mass:
  • Phosphorus (P): \( 4 \times 30.97 \, \text{g/mol} = 123.88 \, \text{g/mol} \)
  • Oxygen (O): \( 10 \times 16.00 \, \text{g/mol} = 160.00 \, \text{g/mol} \)
  • Total molar mass: \( 123.88 \, \text{g/mol} + 160.00 \, \text{g/mol} = 283.88 \, \text{g/mol} \)

• Use the formula: \( \text{moles} = \frac{\text{mass}}{\text{molar mass}} \)
• \( \text{moles} = \frac{89.0 \, \text{g}}{283.88 \, \text{g/mol}} \approx 0.3135 \, \text{mol} \)

• Use Avogadro's number: \( 6.022 \times 10^{23} \, \text{molecules/mol} \)
• Number of molecules: \( 0.3135 \, \text{mol} \times 6.022 \times 10^{23} \, \text{molecules/mol} \approx 1.89 \times 10^{23} \, \text{molecules} \)

The correct answer is \( 1.89 \times 10^{23} \).

Final Answer